As consumer electronics, and particularly audio/visual electronics, become increasingly feature-rich and complicated to operate, the need for standardized, high-bandwidth communications between devices increases. One solution is the High-Definition Multimedia Interface (HDMI) standard. HDMI is a standard for connecting audiovisual appliances that combines high-definition video and multi-channel audio in a single digital interface to provide crystal-clear digital quality over a single cable, with bandwidth to spare to accommodate future enhancements and requirements. HDMI offers significant advantages over analog A/V connections, including the ability to transmit uncompressed digital video and audio content.
HDMI provides an interface between any compatible digital audio/video source, such as a set-top box, DVD player, and A/V receiver, and a compatible digital audio and/or video monitor, such as a digital television (DTV).
Under the HDMI standard, there is an optional protocol, the consumer electronic control (CEC) protocol, which provides high-level control functions between audiovisual appliances interconnected in the HDMI environment. CEC allows users to control all HDMI devices with a single remote and enables high-level functions such as “one-touch play”. The intent of CEC is to distribute commands between A/V components using a common communication protocol.
The CEC protocol is described in the supplement 1 attached to the HDMI standard. While the supplement 1 illustrates the recommended features available in CEC and defines the electrical specification, signaling and bit timings, CEC blocks and frame, etc., there is no solution for the HDMI appliances to handle CEC commands received from the user and from other HDMI appliances. While the CEC protocol provides a standardized way for devices from different manufacturers to communicate with one another, the manner in which the individual devices handle and generate commands, including CEC commands, might differ widely. As such, the device will have increased overhead in configuring its internal command protocols and procedures to be compatible with the standardized protocol, such as CEC.
Therefore, there is the need for a method and a device for receiving a high-level command from a host control unit in an audiovisual device and converting it into low-level electrical signals to be transmitted via a standardized protocol, and for receiving the low-level electrical signals of the standardized protocol and converting the signals into a command which is recognizable to the host control unit.